let obj = {
    name: "zs",
    age: 19
};
console.log(Object.keys(obj));// ["name","age"]
console.log(Object.values(obj));// ["zs",19]
console.log(Object.entries(obj));

let str = "abc";
let res = Object.getOwnPropertyDescriptor(str,"length");
let res2 = Object.getOwnPropertyDescriptor([1,2],"length");
let res3 = Object.getOwnPropertyNames(obj,"length");
console.log(res3);